Equality and a strong sense of partnership are important to any marriage. But when Bill and Melinda Gates first started dating, they weren't on an even playing field. He was the CEO and founder of Microsoft, while she was a product manager at the company. Melinda later said her relationship with her husband of 23 years has changed over time.

"We've had to change to really be coequals," she told Fortune. "It's not something that immediately happens overnight, but we're both committed to it." Today, the couple even runs their namesake powerhouse philanthropic organization together.

Some analysts believe Amazon is on track to become the first trillion dollar company in the world. However, Amazon founder Jeff Bezos and his novelist wife MacKenzie are what family friend Danny Hillis called "such a normal, close-knit family, it's almost abnormal," according to Vogue.

Until 2013, MacKenzie still drove the couples' four children to school and then dropped Jeff off at work in their Honda. And, to this day, the Amazon CEO avoids scheduling meetings in the morning in order to spend quality time with his wife of 24 years. In an interview with his brother Mark, he said he also avoids checking his phone during family time. Maintaining a strong sense of normalcy is clearly a key part of the Bezos' relationship.

In a Facebook post, Spanx founder Sara Blakely wrote about the "opposites attract" nature of her relationship with her husband of nine years, Marquis Jets founder Jesse Itzler. "He eats fruit until noon, I don't. He likes old school rap, I like old school 70s & 80s. He's a New Yorker, I grew up on Clearwater Beach, Fl. He can run 100 miles, I can run 1. I live to eat, he eats just to live."

Blakely also explained their unique strategies for dealing with marital discord — playing rock, paper, scissors to sort out disagreements and slow dancing after fights. The quirky tactics serve as a way to keep things light, even in the wake of a blowout argument.

For much of his life, Berkshire Hathaway chairman Warren Buffett did not take part in a traditional marriage. While he remained married to his first wife, Susan, from 1952 till her death in 2004, he lived with Astrid Menks. Menks and Buffett didn't tie the knot until 2006, two years after Susan died. The three got along well, and even sent out Christmas cards together — signed Warren, Susan, and Astrid.

While the arrangement may have looked unusual to outsiders, it apparently worked for all those involved. "Unconventional is not a bad thing," Buffett's daughter, Susie Buffett, told the New York Times. "More people should have unconventional marriages."